<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

</head>
<body>
    <button>点击事件</button>
    <ul>
        <li>李东宇</li>
        <li>邓帅</li>
    </ul>
</body>
<script src="jquery.3.4.1.js"></script>
<script>
    $('button').click(function () {
        alert('wahaha')
    })

</script>
</html>